The sources of per- and polyfluoroalkyl substances(PFASs)in Liaohe River Basin and its distribution characteristics and changing trends in surface water, sediments and organisms are summarized. The PFASs can enter the water environment through three ways: production and use, tail water discharge from sewage treatment plants and atmospheric transport and degradation of volatile precursors. The occurrence status of PFASs in different environmental media is different. The concentration of PFASs in surface water tends to increase with time, with short-chain PFASs and perfluorooctanoic acid(PFOA)being the most abundant PFASs. The mass ratio of PFASs in sediments decreases with time, with PFOA and perfluorooctane sulfonate(PFOS)being predominant. PFOS is dominant in biota. The ecological risk assessment methods of PFASs are compared and analyzed, and the ecological risk status of PFASs in Liaohe River Basin is expounded. It is suggested that the scientific research and management of PFASs should be further strengthened at watershed scale.